本計畫將針對離散時間之強健濾波問題進行研究，並將著重在探討該濾波系統在 有限(或指定)頻段中之頻率響應。至今，關於此主題仍僅有少數之研究成果。故 吾人將延伸過去一年計畫中所得到之重要結果，並依照三種不同形式(狀態空間 多邊形系統、頻域多邊形系統、Δ − P − K 系統)之擾動系統提出不同之新型濾波 器設計辦法。同時，吾人將(反向)應用投影引理(projection lemma)推導出全頻段 以及指定頻段之性能條件分析式，預計成果將包含連續時間以及離算時間之性能 分析式。與現有之分析式比較，可知引進額外的新變數之作法，使得吾人擬提出 之條件在估測不同擾動系統之強健性上將得到較不保守的結果。此外，相關之研 究成果預期也將應用至全/指定頻段之多目標以及狀態回授之模糊控制問題等研 究主題。In this project, we will investigate discrete-time robustH∞ filtering problem in finite frequency domain. The problem is new and only very few results have been addressed in the literature. Based on the recently developed key results for the last project, we will propose new filter design method with respect to the following three well-recognized linear perturbed systems: the state-space polytopic systems, the frequency-domain polytopic systems, and the systems with linear fractional parametric uncertainty. On the other hand, we will derive new performance conditions in both finite and the entire frequency domains (for both discrete-time and continuous-time cases) by repeatedly applying the projection lemma in reciprocal operation. It is expected that new conditions with more slack variables will be obtained, and less conservative results of robustness analysis problem will be derived under the aforementioned conditions. Application to finite/full frequency multi-objective filtering or robust filtering problems and state feedback fuzzy control synthesis problem will also be investigated.